Telescoping tube assembly



Oct. 1969 c. H. GARRETTE, JR.. ETAL 3,474,833

IELESCOPING TUBE ASSEMBLY Filed Aug. 26, 1966 Fig.3 24 26 INVENTORS Char/es H. Garret/e, Jn H A R R Y Michael Ryan 56:0, PM n4m 9 .4

ATTORNEYS United States Patent 3,474,833 TELESCOPING TUBE ASSEMBLY Charles H. Garrette,'Jr., and Harry Michael Ryan, Richmond, Va., assignors to Armed Forces Equipment Development Corporation, Richmond, Va.

Filed Aug. 26, 1966, Sen-No. 575,441 Int. Cl. F161 27/12 U.S. Cl. 138-120 4 Claims The invention relates to a telescoping tube assembly and, more particularly, to such a tube assembly in which a plurality of tubes .of varying diameter are arranged in a telescoping position and are adapted to be extended to provide a mast or the like of considerable height, and further adapted to be retracted while not in use.

Such assemblies are well known and have many uses, such as for fishing poles, game equipment, antenna masts and any other use where it is desired to erect a portable pole or mast of a considerable height, which can be disassembled easily into a package that is not bulky and can be easily transported.

In eifecting an extension of a given tube of these known assemblies within its next outer tube, it has been common. to utilize a spring based pin in the first tube which extends outwardly therefrom and into a hole provided in the next outer tube. When it is desiredto retract the extended tube, the pin is manually pressed inwardly to a position without the hole in the next outer tube to enable the inner tube to be retracted into the outer tube. However, these known arrangemens suifer from several deficiencies.

Specifically, the tubes used in these type arrangements must be of a relatively small size since the pins are limited in the amount of weight they can support, mainly due to the fact that the distance which they can extend outwardly from the next outer tube while supporting a given tube is limited, since, otherwise, a binding would occur when the next outer tube itself is being retracted, and the pins would be chipped when contacting the top portion of the tube which receives the next outer tube.

Another problem encountered 'by the known arrangements is that these support pins, due to their shape, would tend to catch and pinc-hthe hand or finger when a section was lowered.

A third problem occurring in these known arrangements is the occurring of a shock on the tubes when a given tube is retracted to the bottom of the assembly, which leads to an elongation of the holes of the tubes which are supporting extended tubes.

It is therefore an object of the present invention to provide a telescoping tube assembly which permits the pin supporting a given tube to extend outwardly from the supporting tube to provide additional support, while overcoming the disadvantages discussed above.

It is a further object of this invention to provide a tube assembly having support pins with a unique cam surface in order to permit the extending pin to be cammed inwardly during retraction of a given tube to prevent binding of the tubes, chipping of the pins, and chipping of the top of the next outer tube section.

It is a further object of this invention to provide a telescoping tube assembly which eliminates the shock occurring on the extended tubes when a given tube is retracted thus preventing elongation of holes in which the support pins extend.

Briefly summarized, the present invention provides a tube assembly having a plurality of telescoping tubes of varying diameter, all but one of which is provided with a spring urged pin in the bottom adapted to extend completely through a corresponding hole provided with a cam of the next outer tube. Each pin is provided with a cam surface which is dammed inwardly when the tube supporting a given tube is itself retracted into its next outer 3,474,833 Patented Oct. 28, 1969 "ice tube, the camming occurring by engagement of the pin with the upper end of the latter next outer tube.

A plurality of horizontal slots may further be prov1ded in the tubes in alignment with their pin receiving holes in order to maintain the tubes in axial alignment, and a rubber plug can be provided in the bottom of at least the outermost tube in order to absorb shocks occurring when each individual tube is retracted.

Further and other objects of this invention will become apparent from the description of the accompanying drawings in which like numerals refer to like parts.

FIGURE 1 is a perspective view of the tube assembly in an extended position;

FIGURE 2 is a vertical sectional view of the tube assembly depicting a portion of the tubes being retracted and a portion extended;

FIGURE 3 is a vertical sectional view of the tube assembly depicting the tubes in their retracted position; and

FIGURE 4 is an enlarged vertical sectional view, partially cut away, showing the cooperating parts as a tube is being retracted into its next outer tube.

Referring specifically to the drawings, FIG. 1 depicts the tube assembly, shown in general by the reference numeral 10, in its extended position. The assembly comprises a plurality of individual tube sections which may vary'in number and length according to height requirements. In the particular example shown, ther are seven sections, each approximately 5 feet in length, this length varying slightly between tubes, as will be explained in detail later.

Referring specifically to FIG. 2, which depicts the assembly ina partially contracted position, tubes 12, 14 and 16 and their associated components are shown by example, it being understood that the remaining tubes all are similarly constructed and arranged.

Referring specifically to tube 12, which is shown in its extended position, there is provided a pin 18, the head of which is cammed in a housing 20, the latter being mounted flush with the bottom end of tube 12. Spring 22 is disposed in'housing 20 and urges the free end of pin 18 outwardly through a hole 25 in the lower portion of tube 12.

As seen in FIG. 2, pin 18, in the extended position of tube 12, extends completely through a hole 24 provided near the upper end of the next outer tube 14, the end of pin 18 extending a small distance outwardly from tube 14 to insure a more stable support of tube 12.

The tubes may be of a varying length, the length of the tube 16 being greater than tube 14 by an amount corresponding to the distance housing 20 extends into tube 14. In this manner, the upper ends of the tubes are flush when all of the tubes are in their retracted position, as shown in FIG. 3.

Also, due to the staggered length of the tubes, an inwardly camming of pin 18 of tube 12 is eifected by engagement of this pin with the top end of tube '16 as tube 14 is telescoped inwardly into tube 16. This camming is better shown with a reference to FIG. 4 and is aided by the tapered cam surface formed on the end of pin 18, said surface being more clearly shown in FIG. 4. When tube14 has been completely withdrawn into tube 16, the bottom end thereof abuts the top of the housing of tube 16 and pin 18, which has been cammed inwardly by engagement with the top end of tube 16, will subsequently extend outwardly, under the action of spring 22, into hole 26.

It is thus seen by this arrangement, as the tubes are withdrawn in order from the lowermost to the uppermost, the pins which are supporting the next upper tube to the one being withdrawn will each be aligned within a series of holes including holes 24 and 26 of tubes 14 and 16,

respectively, as shown in FIG. 3. This, of course permits the entire series of tubes to be retracted at the same location by a manual pressing inwardly of the pin of the tube to be retracted. For example, after tube 14 has been completely retracted, pin 18 will be aligned with the series of holes including holes 24 and 26 and can be depressed by manual pressure applied through these holes. Tube 12 will then be retracted and the pin of the next inner tube will align with these holes for retracting the latter tube, and so on.

As an alternate feature of the present invention, a longitudinal groove may be provided in each tube in alignment with the holes therein in order to provide a track in which the pin of the next inner tube rides when the inner tube is being retracted.

These grooves are shown in FIG. 4 by dotted lines 30 and 32 on tubes 14 and 16, respectively, groove 30 being utilized to guide pin 18 when tube 12 is retracted into tube 14 and groove 32 being utilized to guide the pin (not shown in FIG. 4) of tube 14 as the latter is being retracted into tube 16, to maintain the tubes in a constant axial relationship. As an added advantage of these grooves, it should be noted that just prior to tube 14 being completely retracted within tube 16, as shown in FIG. 4, pin 18 will ride in that portion of groove 32 extending above hole 26, which of course afiords added stability to the entire assembly since groove 32 will have the pin of tube 14 riding in its lower portion as well as pin 18 riding in its upper portion.

It is also within the scope of the invention to vary the relative lengths of the housings extending in one end of each of the various tubes in order to permit the other ends of the tubes to be flush when they are retracted. In this arrangement the tubes themselves may be of the same length, or they also may be of varying lengths, as discussed above.

As a further alternate feature of the present invention, a rubber plug 36 may be disposed in the bottom portion of the outermost tube, as shown in FIGS. 2 and 3. The plug may be of any reasonable thiclcness, for example /2, and will absorb a substantial amount of the shock caused by each tube as they are retracted into the outermost tube, thus minimizing shock on the various holes, as explained above.

While the foregoing assembly is described as a preferred embodiment of the invention, it is to be understood that certain changes, alterations, modifications and substitutions can be made without departing from the spirit and scope of the appended claims.

What is claimed is: I

1. A tube assembly comprising a plurality of telescoping tubes of varying diameter, a spring urged pin located in the lower portion of all of said tubes but the outermost one, a hole formed through the upper'portion of all of said tubes but the innermost one, the pin of a given tube adapted to extend completely through the hole of the next outer tube to maintain said given tube in an extended position, the end of each of said pins extending outwardly from the next outer tube and having a cam surface so that, when said next outer tube is telescoped within its next outer tube, said pin is cammed inwardly by the end of said latter next outer tube.

2. The assembly of claim 1 wherein said spring is disposed in a housing terminating flush with the lower end of each of said tubes, each of said tubes having a length varying from the length of its next outermost and innermost tube by an amount corresponding to the length of said housing so that, in a retracted position, the upper ends of said tubes are flush, and their holes aligned.

3. The assembly of claim 1 wherein an internal guide track is formed in all of said tubes but the innermost one, said track extending the length of each tube in alignment with said hole, the pin of a given tube being adapted to ride in the track of the next outer tube when extending and retracting said given inner tube to maintain said tubes in a constant axial relationship.

4. The assembly of claim 3 wherein, when said next outer tube is telescoped into its next outer tube, the pin from said given tube rides into a portion of the track of said latter next outer tube after being cammed inwardly by the end of said latter next outer tube.

' References Cited UNITED STATES PATENTS 2,232,824- 2/ 1941 Maher 285-298 3,081,999 3/1963 Harris 285-298 3,153,252 10/ 1964 Ricciardi 285302 PATRICK D. LAWSON, Primary Examiner US. Cl. X.R. 285-302 

1. A TUBE ASSEMBLY COMPRISING A PLURALITY OF TELESCOPING TUBES OF VARYING DIAMETER, A SPRING URGED PIN LOCATED IN THE LOWER PORTION OF ALL OF SAID TUBES BUT THE OUTERMOST ONE, A HOLE FORMED THROUGH THE UPPER PORTION OF ALL OF SAID TUBES BUT THE INNERMOST ONE, THE PIN OF A GIVEN TUBE ADAPTED TO EXTEND COMPLETELY THROUGH THE HOLE OF THE NEXT OUTER TUBE TO MAINTAIN SAID GIVEN TUBE IN AN EXTENDED POSITION, THE END OF EACH OF SAID PINS EXTENDING OUTWARDLY FROM THE NEXT OUTER TUBE AND HAVING A CAM SURFACE SO THAT, WHEN SAID NEXT OUTER TUBE IS TELESCOPED WITHIN ITS NEXT OUTER TUBE, SAID PIN IS CAMMED INWARDLY BY THE END OF SAID LATTER NEXT OUTER TUBE. 